I have decided to start a long range plan to build a LZ motor for my truck, and the best thing to get me started is to say so. Now, my current L 20 B is old but runs great, good starter, no oil use, but lacks the power to pull a truck that has gained from 2700 to 3400 lbs. Add to that, tall tires and 4:11 gears, which were all I had to replace the rear end that blew. Adding more hp to an older motor will only shorten the life it has left, and she's been a reliable and faithfull workhorse and deserves better.
My plan, is to attempt a Jason Grey 2.3 LZ hybrid. This weekend I negotiated and bought a Z 22 engine from a 4X4, a standard with flywheel. It's in running condition, so internal parts ok. Cost...$25 I then removed a set of Z 24 pistons from an old block for an additional $5. Total so far $30 plus six pack for lift truck driver to lift motor onto the back of my truck in a couple of weeks.

Last edited by datzenmike on 19 Sep 2013 17:12, edited 4 times in total.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

The block needs to be bored to fit the Z 24 pistons and I have 3 to choose from; an L 20 B ( blown head gasket but no wear ridges ), a Z 20 E '81 200sx, and the Z 22 from an '82 4x4. I would guess that the Z 22 would have the largest bore, so least amount to remove. I would still have to re locate the dip stick and plug the old hole, and use the L 20 engine mounts to tilt the motor for use of the L series transmision. This tilt would mean that I would have to use the L 20 oilpan and pickup as well. Now according to my manual the L 16, L 18, L 20 up to '79 used one size of main bearing, and the '79 and up, and all Z 20, Z 22, Z 24's use a different size. If so then the Z 22 crank won't fit in the L 20 that I have, as I'm sure its an older model. This may preclude the use of the L 20 block and I suppose the best thing to do, is to measure them. Anyway, I'd like to use the L 20, but I know the crank is already in the Z 22.
So I have some cleaning and measuring to do, as well as gaskets and bearings to buy. I'll take pictures and post them (as soon as the last roll is full, so expect some delay). This will help keep up the enthusiasm during the long, dark, wet island nights this winter. Thanks for the encouragment guys!

defdes..... what was involved in stroking your motor? How much?...cost and work. I still have access to the Z 24 block but understand the blocks crack and are heavy. Also the rods are swizzle sticks. When I get the L 20 and Z 22 rods out, I'll get pictures to compare to the Z 24's

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

Went in early to work today so I could leave sooner. The local J/Y closes on long w/ends and I needed to get there before 5, to bring my Z 22 home so I have something to do for the holiday. The head is loosened with a hose or something left to remove. I took the clutch and PP off, it looks ok, flywheel too. Still have to drain oil (4x4 oilpan, have you seen one of these things?) Once rods, pistons and crank are out and block stripped, I plan to use my neighbour's pressure spray washer (8 hp ) to degrease it. Want to get as much done as I can before flying to Ontario to visit my dad on my holidays, he's 86.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

Spent some time this pm stripping down my Z 22. Haven't really worked on one since before some of you were borne. It was fun all the same

The motor and internals are in excellent shape, not siezed after 2 years sitting in J/Y. Cylinders clean with no ridge at top. Pistons popped out. Crank is shiny with lots of oil on bearings, and they show very little wear, or at least no indications of oiling problems. Pistons are un-scuffed and clean.

I compared the rods from the Z 22 and the Z 24 and I have to say that other than length they seem identical in every way. The Z 22's seem quite beefy around the rod bolts and caps. Tomorrow, I plan to tear down a spare L 20 B I have for the oilpan, engine mounts, timing cover, chain, etc for the front of the LZ 23. While i'm at it, i'll pull the rods and compare them to the Z rods. Of course i'll take pictures of them.

BTW. My Chilton truck and the 240sx manuals show the main bearing diameter for '79 and '80 L 20 B and all Z motors as 2.1631"( the same as the L 16, 18) . I measured the Z 22 crank and it was 2.359, the same as the L 20 B , so don't trust the manual! Measure everything!

I still have access to the Z 24 motor I got the pistons out of for the LZ 23. I'd like to pull the crank and see if, or how well it fits an L 20 B block.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

In a way, why not build an LZ 2.4?
We have a couple in 510's within the lower mainland. You get your stroke - consequently the torque you need. I doubt that the extra 17mm of block height will be an issue in your engine bay, unless you are still using the stock carb/air cleaner combo.
Stroke = torque, adding more makes a huge difference.
Keep going on your current path, the change comes in the front cover and timing chain. You'll need two Mercedes master links for the chain, and you'll have to get the front cover welded up on the top side (add that extra 17mm to the deck height. You can get a welder to Tig up the height, and get a machinist to plane it level and drill/tap the two 6mm holes that bolt the head to the front cover.
It's nearly worth the effort. One of our member’s dyno'd his LZ24 this spring, netted 165 ft/lbs of torque, 190 HP AT THE WHEELS!!
Worth the effort - just wanted to pland the bug!
Byron

Some great ideas! Thanks. I drove an '87? truck once and was totally blown away by the torque! Well i'll look into this. As for clearance, there's no problem as there 's a 4 " body lift, tons of room. I thought about the space above the timing cover before and figured that a piece of aluminum plate with holes in the bottom for mounting to cover and holes in the top for the L head with thickness to allow a gasket. I could fab it myself at home if the thickness is right.

I assune that if the block is crack free, that it's now "conditioned" and will remain crack free, or is it a time bomb?

Obviously an L head didn't make all that power alone, do you have a way for me to learn more about this build-up? I have a W-58 peanut that I ported myself, (for better or worse) and a pair of SU's, but need to fab a linkage and a short manifold to the one they came on, or muiti port FI off an '81 200sx, again I would have to make up a manifold. Whatever I build, it will start with a carb and progress from there.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

To make life even easier, why not use the 200SX head and EFI?
If you’re running it in a truck that has bigger tires, and a body lift ect, I'll assume that you are into off road.... and therefore need a torque monster. The L head will not improve torque, only the ability to breath at higher RPM (due to larger ports and valves, with enough meat to port even further). Actually, the port configuration, and valve lay out, of the NapsZ head is more efficient in stock form then the L head (the purpose of it’s intended design). The Z's cross flow design, and staggered valve lay out, give more swirl and better combustion, especially at low RPM's. The NapZ head has smaller ports, but that should not be a problem until you approach the 4500-5000 RPM range - when will you be there? And for how long?
Also for an off road truck, the advantage of EFI is unparalleled. The truck will run at any angle - try that with a float in a carburetor. I helped a good friend build up a Toyota years ago; I couldn't believe the angles that the truck was on, and it still drove like nothing was the matter (and in some instances stayed on all 4 wheels when I figured we were over for sure!). No carbureted vehicle would have still been running – and definitely not a side draft vehicle!

As for complication, the 200SX EFI is pretty simple, especially if you use the 80-81 4-plug unit. This is what I used years ago to do my L series EFI conversion on my 2.2 wagon.

Just a thought, your still in the building stage, thought I'd through it in.

Well, my heart is set on a LZ engine, but as I only have $30 plus a 6 pack invested...? I was hoping to get a little more torque and mid range power with the stroke increase of the Z22 crank. 'Course a Z24 would be even more of the above...hmmmm. And I still have access to the block and head I got the Z 24 pistons out of... I could check for any cracks. BTW checked the Z 22 and its fine

The 200sx FI has the 4 injectors, sensors, wiring and computer. Question... The FI is for a Z 22, if I put it on a larger Z 24 nothing would change would it? The computer would just increase the injector time to compensate for the increased displacement? No one seens to know or can give a straight answer. This is something I would add later on anyway after I get it running.

Pulled an L 20 B apart this sunday pm. Took pix of L 20, Z 22. Z 24 rods w/ pistons. The L 20 and Z 22 look the same (rods) and the Z 24 are the same just longer.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

The 200SX added fuel relative to airflow. So the bigger displacement will just suck more air, and alls well. The parameters that are fixed are the idle and full throttle settings. If you're not ringing the heck out of the thing, there probably won't be an issue. If there is an A/F issue, go to a slightly larger injector......
The EFI is no doubt the way to go, even if it’s the old archaic 200SX system – it’s still leaps and bounds better than a stock carb system.
Byron

I hear that! I have had a dialogue with defdes about adding stroke, and a few things fell into place. I mixed and matched some parts I have, and discovered that Jason Grey had (of coarse) discovered it first. As an option I could try L 20 B rods and block bored to take Z 24 pistons on a Z 24 crank. The pistons need about 1 mm removed from the tops but more would be required to drop the compression down from the estimated 10.24 : 1 even useing an open chamber head. Also the block needs to be clearanced and the counter weights cut? Where would I find this info by Ben Pila?

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs